Rotary-reciprocating tool attachment



April 4, 1967 B. A. AUBERT ROTARY-RECIPROCATING TOOL ATTACHMENT Filed April 15, 1964 BENJAMIN A. AUBERT BY on no W W o ATTORNEYS United States Patent 0 3,312,118 ROTARY-RECIPRQCATING TOOL ATTACHMENT Benjamin A. Aubert, 1141 Knickerbocker Drive, Sunnyvale, Calif. 94087 Filed Apr. 15, 1964, Ser. No. 359,923 7 Claims. (Cl. 74-4243) The present invention relates in general to a device which provides rotational and/or longitudinal movement when driven by a rotating member and more particularly to a rotary-reciprocating tool for use as a sander, cutter or the like.

Broadly stated, the invention, to be described in greater detail below, is directed to a device particularly adaptable as an accessory for a rotary drill press for sanding, filing, cutting and the like. The device includes a housing member, a stem member axially located within the housing member, drive means for driving one of the members longitudinally in either one of two opposite directions with respect to the other member in response to relative rotary motion produced between the two members and means for alternately engaging the drive means to produce relative reciprocating motion between the members in combination with the relative rotational motion between the members.

Typical reciprocating sanders constructed in the past include an axle rotatably mounted adjacent its one end and with its other end supporting a sanding drum which projects through the work supporting table. Rotary motion is provided to the axle, and a cam surface is mounted on the axle to cause the drum to move up and down as the axle rotates. The major difficulty with such sanding devices lies in the fact that the upper end of the sanding drum is unsupported, and since large forces are applied to this upper end by directing the work to be sanded against the drum, large torques are applied to the axle mounting and to the gears through which rotational mo tion is applied to the axle thereby causing heavy wear and short life for the device.

Additionally, the typical reciprocating sander can only be used for sanding operations, or in some cases cutting operations, and cannot be utilized to perfiorm other functions.

In order to provide more versatile machines, attempts have been made to provide as attachments for conven tional drill presses devices which produce rotary reciprocating motion. Two such devices are disclosed in US. patents, No. 2,244,813 to Tomrnerup and No. 2,930,164 to Metoif. These two patents disclose sander attachments for drill presses, and in these attachments the rotary motion of the drill press is utilized to operate the existing drill press handwheel in order to achieve vertical reciprocating motion. Not only are these constructions unduly complicated, but also no support is provided for the base of the sanding element to avoid the undesired effects of high torques produced when work pieces are applied against the sanding element.

Another attempt to produce a rotating sander for use with a drill press is the construction shown in US. Patent No. 2,519,542 to Carey et al. in which an attachment for a drill press utilizes two parallel, spaced apart spindles which are interconnected via a worm gear and a wheel with a driving eccentric. Here again, high torques produced by applying work pieces to the end of the sanding element tend to produce misalignment of the two spindles.

The construction in accordance with the present invention avoids the difiiculties inherent in these prior art constructions by positioning the housing and stem members coaxially and providing relative rotational and longitudinal motion therebetween so that the housing member can be supported at one end of the device and the stem member at the other end of the device. Thus, when the projecting end of the stem member is rigidly held and the housing member rotated, rotary and longitudinally recip rocating motion are applied to the housing member.

Additionally, if the housing member is held against notational motion and rotational motion is provided to the stem member, purely longitudinally reciprocating motion is applied to the housing member.

A number of different work pieces such as sandpaper, a filing surface, or knife blades can be supported on the housing member for permitting performance of a number of additional operations by the drill press on which the attachment is supported and driven.

Other objects of the resent invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent cor-responding parts in each of the several views.

In the drawings:

FIG. 1 is a side elevational view, partially broken away and foreshortened, of a drill press on which a structure in accordance with the present invention is mounted;

FIG. 2 is an enlarged perspective view, partially broken away, of a drill press attachment in accordance with the present invention;

FIG. 3 is an enlarged cross-sectional view of the structure shown in FIG. 2 taken along line 3-3 in the direc tion of the arrows;

FIG. 4 is an enlarged cross-sectional view of the structure shown in FIG. 2 taken along line 44 in the direction of the arrows; and

FIG. 5 is an enlarged cross-sectional view of the structure shown in FIG. 2 taken along line 5-5 in the direction of the arrows. i

While the device in accordance with the present invention will be described hereinafter with respect to utilization in a conventional drill press, it is obvious that the device can be utilized as an attachment to any apparatus providing rotary motion such as, for example, a lathe.

Referring now to FIG. 1, the present invention can be utilized to provide a reciprocating sander attachment generally designated A for a drill press B of the conventional variety including a rotary chuck C in which one end of the sander attachment is held. The lower end of the sander attachment A is held in a clamping member D under the work table E of the drill press, the sander attachment extending through an aperture in the work table E. In the arrangement illustrated in FIG. 1, the handwheel F of the drill press is locked at one specific location to permanently vertically locate the chuck C with respect to the work table E. However, as will be seen below with certain constructions of the sander attachment, the handwheel F need not be locked in position but can permit vertical reciprocating motion on the chuck C as the sanding portion of the attachment F to which it is secured reciprocates up and down as it rotates.

Referring now to FIGS. 2-5, there is shown a reciprocating-rotary sander construction incorporating features of the present invention. The sander attachment A includes a rotating housing 9 with an outer tubular casing 10 on the exterior surface of which is mounted a working member such as, for example, a sleeve of sandpaper 11. Inside the upper end of the casing 10 there is provided a female spline 12 engaged by a male spline 13 which has a machined cylindrical end 14 adapted to be held by the chuck C.

Located within and axially aligned with the tubular casing It) is a stationary stem member 15 which has a smooth machined end 16 projecting from the lower end of the housing 9 through a disc member 17 for rigid support in the clamping member D beneath the work table E of the drill press B. Bearings are provided in the disc member 17 to reduce wear during rotation of the housing 9 with respect to the stern member 15, and centrally of the housing 9 an annular slot 18 is provided in the stem member 15. A central bearing member 19 is rotatably mounted in the slot 18 and this hearing member rotates with the casing as described in greater detail below.

On opposite sides of the annular slot 18, the stem member is provided with diverging threads 21 and 22, the upper threads 21 being, for example, left-hand and the lower threads 22 being righbhand. Slidably fitting within the outer casing 10 and held by, for example, set screws (not shown) isa hollow, cylindrical inner casing 23. This inner casing 23 is also rotatably mounted with respect to the machined end 16 of the stem member 15 by a disc member 24 in the same manner as the disc member 17 described above.

This inner casing 23 is provided with upper and lower pairs of diametrically opposed cylindrical bores 25 and 26 respectively, each pair being axially aligned normal to the axis of the stem member 15. Slidably located in these bores 25 and 26 are upper and lower half nuts 27 and 28 respectively. Each of these half nuts 27 and 28 is circular in cross-section, has an outer surface curved to conform to the exterior cylindrical surface of the casing 23 and has a curved inner surface provided with thread portions which mate with the adjacent threads on the stem member 15. Additionally, each of these half nuts 27 and 28 is resiliently urged radially inwardly toward the stern member 15 by a leaf spring 30 which has its one end fixedly secured in a longitudinal slot 31 in the casing 23 and its other end resting in a longitudinal slot 32 in the exterior surface of the half nut.

For disengaging the upper and lower pairs of half nuts 27 and. 23 from the threads of the stem member 15 are pairs of upper and lower cam spacers 33 and 34 respectively, the cam spacers being supported on the end of joining bars 35 which extend longitudinally of the stem member 15. Two joining bars 35 are provided in the assembly spaced apart and slidably extending through slots 36 in the central bearing member 19, each bar 35 supporting an upper cam spacer 33 at its one end and a lower cam spacer 34 at its other end. The bars 35 are of a length approximately equal to the distance between the centers of the upper and lower half nuts 27 and 28 such that, at any given time, only one of the cam spacers at its ends is operatively positioned between a pair of half nuts to disengage that pair of half nuts from the threads of the stem member 15 while permitting engagement of the other pair of half nuts with the threads of the stern member. In the preferred embodiment of the present invention, in order to maintain the spacers 33 and 34 and the bars 35 out of contact with the stern threads, these members are cut froma single tubular member, and the bars 35 connect two tubular segments on which the spacers 33 and 34 are formed.

Each joining bar 35 is provided with an upper and a lower stop 37 and 38 respectively which, during operation of the device, engage the central bearing member 19 when the housing 9 reaches the lower and upper limits of its vertical reciprocating motion, respectively, as pointed out in greater detail below in the description of the operation of the device.

In order to maintain alignment and permit the joining bars 35 to move longitudinally with respect to the inner housing 23 for disengagement of the pairs of half nuts, each of the joining bars is provided with a radially outwardly extending alignment tab 39 which slides vertically in a vertically aligned longitudinal slot 41 in the inner casing 23.

The device operates as follows: with the lower machined end 16 of the stem member 15 rigidly held against rotation and translation, the housing 9 is rotated by means of the male spline 13 and the associated members including the casings 10 and 23, the half nuts 27 and 28, the cam spacers and joining bars 33, 34 and 35 and the central bearing member 19 are rotated relative to the stem member 15. Due to the action of the male and female splines 12 and 13, the housing 9, including all these associated members except the bearing member 19 is free to reciprocate vertically as it rotates. As the housing rotates it is caused to move vertically in one direction by the engagement of one pair of half nuts with the associated stem thread. As shown in FIG. 2 with the housing :rotating clockwise and the upper half nuts 27 engaged with the left-hand thread on the stem member 15, the housing is caused to move vertically upward on the stem member until the lower stops 38 contact the central bearing member 19. The joining bars 35 with their cam spacers 33 and 34 slide up and down through the slot 36 in the hearing member 19 as the housing 9 moves up or down.

When the stop strikes the central bearing member at the end of the vertical stroke, the casings 10 and 23 continue to move in the same vertical direction while the bars 35 are held against movement so that the cam spacers 33 and 34 at the ends of the bar serve to disengage that set of half nuts which has been engaged with the stern threads and to allow engagement of the other set of half nuts whereby, upon continued rotation of the casings 10 and 23 in the same direction, vertical motion of the hous ing 9 with respect to the stem member 15 is reversed. Thus, while the housing 9 is rotating in one direction, it is caused to reciprocate up and down.

Obviously certain alternatives and modifications are possible with the present invention. For example, since in the conventional drill press the handwheel F permits vertical movement of the chuck C as the chuck C rotates due to the rotating shaft being journalled for vertical movement in a drive wheel, the housing 11 can be directly held by the chuck C with the journalled drive shaft of the drill press allowing vertical motion during rotational drive thereby avoiding the necessity for the male and female spline members 12 and 13 described above. Naturally, the casings 1t) and 23 can be one single member provided with bores to receive the half nuts.

Additionally, while the preferred embodiment includes the provision of diverging threads on the stem member and engageable and disengageable half nuts mounted on the inner casing 23, the reciprocating sander can be constructed with diverging threads on the casing 23 and engageable half nuts mounted on the stem member.

Also, while the invention has been thus far described in detail with respect to a rotating and reciprocating mem ber driven by a rotating shaft if the housing 9 is held against rotational motion by the male spline 13 but permitted to reciprocate vertically on the spline 13 and. the stem member 15 rotated by means of the machined end portion 16, the housing 9 will be caused to reciprocate up and down without rotational motion to provide either a filing or cutting action depending upon the Work member or tool mounted on the housing 9.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention as limited only by the scope of the appended claims.

It is claimed:

1. A rotary-reciprocating tool comprising, in combination: a housing member, a stem member axially located Within said housing, means for rotating one of said members with respect to the other of said members while permitting relative longitudinal movement between said members, first drive means mounted between said members for driving one or" said members longitudinally with respect to the other of said members during relative rotation, second drive means mounted between said members for driving said one of said members longitudinally 5 with respect to said other of said members, and means for continuous alternate engagement of said first drive means and then second drive means whereby said memers are reciprocated relative to one another so long as said means for rotating is actuated.

2. A rotary-reciprocating tool comprising, in combi nation: a housing, means for rotating said housing While permitting longitudinal movement of said housing, a stem member axially located Within said housing, first drive means mounted on said stern member for driving said housing longitudinally in one direction, second drive means mounted on said stem member for driving said housing longitudinally in a direction opposite to said one direction, and means for alternately engaging said housing with said first and then said second drive means as said housing is rotated by said rotating means.

3. A rotary-reciprocating tool comprising, in combination: a housing member, a stem member axially located Within said housing, means for rotating one of said members relative to the other of said members While permitting relative longitudinal movement between said members, oppositely directed thread means mounted on said stem member, and means for continuous alternate engagement of said first drive means and then said second drive means whereby said members are reciprocated relative to one another so long as said means for rotating is actuated.

4. A rotary-reciprocating tool comprising: a housing member, a stem member axially located within said housing and provided with a pair of diverging threads, means for rotating one of said members relative to the other of said members While permitting relative longitudinal movement between said members, and means for alternately engaging said housing member with first one and then the other of said diverging threads including pairs of half nuts slidably mounted in said housing member for engagement with said diverging threads, springs means urging each pair of said half nuts toward one of said diverging threads, cam members rotatable with said housing for alternately disengaging first one pair of said half nuts and then the other pair of said half nuts from said threads on said stem member at the longitudinal limit of said housing, and stop members for actuating said cam members at the longitudinal limit of said housing.

5. The tool of claim 4 wherein said means for rotating one of said members relative to the other of said ill members includes a first spline member formed in one end of said housing member and a second spline member mating and engageable with said first spline member and adapted for mounting in a rotatable chuck.

6. A rotary-reciprocating tool comprising: a housing member, a working tool in said housing member, a stem member axially located Within said housing and provided with a pair of diverging threads, means for rotating one of said members relative to the other of said members while permitting relative longitudinal movement between said members, and means for alternately engaging said housing member with first one and then. the other of said diverging threads including pairs of half nuts slida-bly mounted in said housing member for engagement with said diverging threads, spring means urging each pair of said half nuts toward one of said diverging threads, 2 pair of cam members rotatable with said housing mem' ber and slidable between the associated half nuts of each pair of half nuts from the threads on said stern member at the longitudinal limit of said housing, means connecting said pairs of cam members for permitting only one pair of half nuts to engage the threads on said stem member at any one time and a rotatable ring member having a slot through which said connecting means passes, said stem member provided with means for rotatably mounting said ring member thereon and said connecting means provided with stop members engageable with said ring member at the longitudinal extent of said housing for actuating said cam members to disengage the engaged pair of half nuts and engage a disengaged pair of half nuts with the stem member.

'7. The tool of claim 6 wherein said means for rotating one of said members relative to the other of said members includes a first spline member formed in one end of said housing member and a second spline member mating and engageable with said first spline member and adapted for mounting in a rotatable chuck.

References Cited by the Examiner UNITED STATES PATENTS 2,604,788 7/1952 Hauber 74-4248 2,731,121 1/1956 \Venstrom 74-424.8

DAVID J. WILLIAMOWSKY, Primary Examiner. L. H. GERIN, Assistant Examiner. 

1. A ROTARY-RECIPROCATING TOOL COMPRISING, IN COMBINATION: A HOUSING MEMBER, A STEM MEMBER AXIALLY LOCATED WITHIN SAID HOUSING, MEANS FOR ROTATING ONE OF SAID MEMBERS WITH RESPECT TO THE OTHER OF SAID MEMBERS WHILE PERMITTING RELATIVE LONGITUDINAL MOVEMENT BETWEEN SAID MEMBERS, FIRST DRIVE MEANS MOUNTED BETWEEN SAID MEMBERS FOR DRIVING ONE OF SAID MEMBERS LONGITUDINALLY WITH RESPECT TO THE OTHER OF SAID MEMBERS DURING RELATIVE ROTATION, SECOND DRIVE MEANS MOUNTED BETWEEN SAID MEMBERS FOR DRIVING SAID ONE OF SAID MEMBERS LONGITUDINALLY WITH RESPECT TO SAID OTHER OF SAID MEMBERS, AND MEANS FOR CONTINUOUS ALTERNATE ENGAGEMENT OF SAID FIRST DRIVE MEANS AND THEN SECOND DRIVE MEANS WHEREBY SAID MEMBERS ARE RECIPROCATED RELATIVE TO ONE ANOTHER SO LONG AS SAID MEANS FOR ROTATING IS ACTUATED. 